Mobile App deals: Tether, Pocket Informant, Grooveshark

A couple of popular mobile apps are on sale at deep discounts right now.

Tether is a popular BlackBerry app which lets you connect a phone to a PC or Mac to let you access your 3G internet connection from a computer — without necessarily letting your wireless carrier know what you’re up to and impose extra data charges.Normally Tether runs $49.99, but you can get it for a limited time for $24.99.

Pocket Informant is a popular calendar and task manager app for mobile devices. The iPhone and iPod touch version normally runs $12.99, but it’s currently available for $4.99 as part of a “MacWorld Expo Sale.”